From what I can see, simply installing the push in breakers looks like it is enough to scratch the coating on the aluminum busses. IDK, maybe that is the manufacturer’s intent. The salt air on the water front around here just seems to annihilate those aluminum panel busses. Seems some manufacturers make the effort put a little dab of inhibitor or grease on their CB pressure contacts, while others leave theirs completely dry. I would think that the inhibitor should help keep out moisture and make more of a so called oxygen free connection, but maybe not. I will still install the Siemens panels with the aluminum buss, but will usually try and get them with the copper buss if possible, since the price isn’t that much more.
Im working on a siemans panel in the bay area whwere the fog seems to come in HO called that the washer/dryer was having trouble and she had some guy out who checked a few things and went away. problem was still was intermittant, would lose power to run and the LG electronics on the units would start flashing wildly. I came out and the interior cover from the main outside panel was missing, they said its been like that ever since they moved in 3 years ago, the buss was corroded something awful and the suspect breaker was almost welded to the buss, the circuit wiring was new since they had the furnace and water heater moved.....its a ite panel at least that is the maker on the 100 amp main this is the older panel where the buss is against the outside wall. newer ones theyve moved it to the main/load divider partition. any experience with these panels and loose breakers or under thickness buss some breakers seem a little loose? CRS